Simulation of Store Separation Scaling Requirements for Wind Tunnel Experiments and Validation of Numerical Simulations

Abstract

The results of experimental and numerical investigations on cargo drop tests from a generic military transport aircraft configuration with open cargo bay are presented. The governing equations for experimental scaling are derived and it is shown, that a correct scaling is difficult to ensure. In the dropping experiments conducted in the DNW-NWB wind-tunnel the trajectories of cargos with increasing complexity were measured three-dimensionally to provide reliable data for the validation of the numerical airdrop simulation. The repeatability of the tests is very good, even for very lightweight aerodynamically sensitive cargos. Based on the DLR-TAU-Code a process chain for the coupled solution of aerodynamics and flight-mechanics was developed. Its results match well the experimental data although attention has to be paid in specifying the initial conditions because they may, as expected, have an impact on the solution.